Eylem Kaya | The University of Auckland (original) (raw)

Papers by Eylem Kaya

ABSTRACT 1. Kaya, E., Onur, M., Satman, A. (2005), "The Effect of CO2 on Reservoir and P... more ABSTRACT 1. Kaya, E., Onur, M., Satman, A. (2005), "The Effect of CO2 on Reservoir and Production Performance of Geothermal Systems", " Turkish Journal of Oil and Gas, Vol. 11, No. 1, Feb 2005, 27-36 (in Turkish)

Geothermics, 2021

Abstract This work examines the use of pressure drop in geothermal steam lines using a continuum ... more Abstract This work examines the use of pressure drop in geothermal steam lines using a continuum approach to the implementation of risk-based analysis. The study is performed by observing the behaviour of changes in pressure drop along the steam pipeline in the Kamojang geothermal field. The relevance of this study is in the context of the implementation of physical asset management based on the PAS 55 guidelines that emphasise risk-based management. This is using the risk-based inspection (RBI) method utilising the API RP-580 standard. Application of flow analysis as a continuum risk-based approach in asset integrity management system is feasible due to its ability to be performed while the equipment is online. It can serve as a first tear assessment before conventional pipeline thickness measurements for setting an effective and efficient maintenance program. This method is also suitable for pipelines that are difficult to access with conventional thickness measurement methods. Steam pipelines in dry fields can have a higher thining rate and effectively shortened life when compared with steam lines from two-phase and wet geothermal fields due to the limited silica carryover. The steam pipeline for Kamojang Unit 4 is in reasonable conditions to continue operating for its intended lifetime of 30 years. Steam washing with slightly mineralised (SiO2 and Cl rich) water/brine is recommended to extend the life of the pipeline.

Geothermics, 2021

Abstract Reinjection is key to maintaining and managing geothermal resources during utilization. ... more Abstract Reinjection is key to maintaining and managing geothermal resources during utilization. This study presents an updated review of the worldwide reinjection experience in geothermal fields. Data from 152 geothermal fields from around the world were used to investigate the impact of reinjection location, reinjection depth, distance from production wells, reinjection fluid temperature, and the amount of reinjection fluid. Positive and detrimental effects on the relevant reservoirs were assessed. Changes in reinjection strategies in response to production and the lessons learned from reinjection experiences in various fields are also discussed. This updated review demonstrates the importance of understanding the type of geothermal system before starting reinjection. Main challenges to successful reinjection are also reviewed along with possible solutions with particular emphasis on pressure support, cooling mitigation, injectivity, scaling and solid deposition, microearthquake and tracer testing.

International Journal of Greenhouse Gas Control, 2020

Abstract In response to global warming, it is important to explore alternative disposal technolog... more Abstract In response to global warming, it is important to explore alternative disposal technologies for greenhouse gas emissions in the geothermal power sector. One alternative which has received widespread focus is co-injection of non-condensable gases with the waste fluids from geothermal operations. Passarella et al. (2015) simulated the interaction between brine with dissolved CO2 and H2S, and a sample of greywacke in their laboratory. The present work aimed to numerically model the results from the experiment using TOUGHREACT. The goal of this study was to develop numerical simulation techniques to investigate the effects of the reinjection of brine with dissolved NCG. The resulting model provided insights into the geochemical interaction of greywacke with brine-NCG solutions under simulated reservoir conditions. The numerical simulations show that mineral dissolution occurred to a greater degree than precipitation, leading to increased permeability and porosity. It was also observed that the mineral reactive surface areas evolved as mineral dissolution progressed, through etch pit formation. Additionally, flow rate had an impact on the overall reaction rates such that a decrease in injection rate led to a corresponding decrease in reaction rates. Lastly, both experimental data and model outputs indicated that CO2 was minimally sequestered in the simulation, while H2S was clearly captured as pyrite. A similar numerical investigation was conducted on the co-injection of NCG with steam condensates subsequently. The modelling results indicate predominant mineral dissolution, CO2 is expected to be captured as magnesite within the reactor, while H2S is still captured as pyrite.

geothermal-energy.org

In this study, 3D visualization of temperature distribution in the Kizildere geothermal system an... more In this study, 3D visualization of temperature distribution in the Kizildere geothermal system and low resistvity distribution in Salavatli geothermal system were built using 3D interpolation and extrapolation techniques. The 3D visualisations are illustrated; ...

pangea.stanford.edu

PROCEEDINGS, Thirty-Sixth Workshop on Geothermal Reservoir Engineering Stanford University, Stanf... more PROCEEDINGS, Thirty-Sixth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, January 31 - February 2, 2011 SGP-TR-191 ... REINJECTION INTO LIQUID-DOMINATED TWO-PHASE GEOTHERMAL SYSTEMS

b-dig.iie.org.mx

Proceedings World Geothermal Congress 2010 Bali, Indonesia, 25-29 April 2010 ... Modelling of Inj... more Proceedings World Geothermal Congress 2010 Bali, Indonesia, 25-29 April 2010 ... Modelling of Injection into Vapour-Dominated Geothermal Systems ... Department of Engineering Science, University of Auckland, Private Bag 92019, Auckland, New Zealand e.kaya@ ...

International Journal of Greenhouse Gas Control

International Journal of Greenhouse Gas Control

This work addresses the feasibility of reinjecting H2S and CO2, captured and dissolved in effluen... more This work addresses the feasibility of reinjecting H2S and CO2, captured and dissolved in effluents from the geothermal field, back into the geothermal reservoir. A series of numerical modelling scenarios was used to assess the effect of NCG (non-condensable gases) reinjection on energy recovery, understand permanent trapping, and forecast potential NCG breakthrough into production wells. Although the gas species from geothermal systems typically have moderate solubility in water, formation of gas phases at lower pressures and/or the shallow subsurface requires careful consideration of the injection rate and composition of NCG. Possible fluid paths and distribution of gas components were investigated to estimate the NCG storage capability of a reservoir, and evaluate the potential risk of the reinjected NCG growing into fingers that may lead to an early breakthrough or potential leakage to the ground surface. Modified versions of benchmark geothermal reinjection models were constructed with initial conditions of a liquid-dominated geothermal system. The results obtained show that the effects of injection depend on the reinjection and production wells arrangement and the recharge conditions. The risk of leakage to the surface is very limited since the injected NCG remain in the liquid phase.

ABSTRACT 1. Kaya, E., Onur, M., Satman, A. (2005), "The Effect of CO2 on Reservoir and P... more ABSTRACT 1. Kaya, E., Onur, M., Satman, A. (2005), "The Effect of CO2 on Reservoir and Production Performance of Geothermal Systems", " Turkish Journal of Oil and Gas, Vol. 11, No. 1, Feb 2005, 27-36 (in Turkish)

Geothermics, 2021

Abstract This work examines the use of pressure drop in geothermal steam lines using a continuum ... more Abstract This work examines the use of pressure drop in geothermal steam lines using a continuum approach to the implementation of risk-based analysis. The study is performed by observing the behaviour of changes in pressure drop along the steam pipeline in the Kamojang geothermal field. The relevance of this study is in the context of the implementation of physical asset management based on the PAS 55 guidelines that emphasise risk-based management. This is using the risk-based inspection (RBI) method utilising the API RP-580 standard. Application of flow analysis as a continuum risk-based approach in asset integrity management system is feasible due to its ability to be performed while the equipment is online. It can serve as a first tear assessment before conventional pipeline thickness measurements for setting an effective and efficient maintenance program. This method is also suitable for pipelines that are difficult to access with conventional thickness measurement methods. Steam pipelines in dry fields can have a higher thining rate and effectively shortened life when compared with steam lines from two-phase and wet geothermal fields due to the limited silica carryover. The steam pipeline for Kamojang Unit 4 is in reasonable conditions to continue operating for its intended lifetime of 30 years. Steam washing with slightly mineralised (SiO2 and Cl rich) water/brine is recommended to extend the life of the pipeline.

Geothermics, 2021

Abstract Reinjection is key to maintaining and managing geothermal resources during utilization. ... more Abstract Reinjection is key to maintaining and managing geothermal resources during utilization. This study presents an updated review of the worldwide reinjection experience in geothermal fields. Data from 152 geothermal fields from around the world were used to investigate the impact of reinjection location, reinjection depth, distance from production wells, reinjection fluid temperature, and the amount of reinjection fluid. Positive and detrimental effects on the relevant reservoirs were assessed. Changes in reinjection strategies in response to production and the lessons learned from reinjection experiences in various fields are also discussed. This updated review demonstrates the importance of understanding the type of geothermal system before starting reinjection. Main challenges to successful reinjection are also reviewed along with possible solutions with particular emphasis on pressure support, cooling mitigation, injectivity, scaling and solid deposition, microearthquake and tracer testing.

International Journal of Greenhouse Gas Control, 2020

Abstract In response to global warming, it is important to explore alternative disposal technolog... more Abstract In response to global warming, it is important to explore alternative disposal technologies for greenhouse gas emissions in the geothermal power sector. One alternative which has received widespread focus is co-injection of non-condensable gases with the waste fluids from geothermal operations. Passarella et al. (2015) simulated the interaction between brine with dissolved CO2 and H2S, and a sample of greywacke in their laboratory. The present work aimed to numerically model the results from the experiment using TOUGHREACT. The goal of this study was to develop numerical simulation techniques to investigate the effects of the reinjection of brine with dissolved NCG. The resulting model provided insights into the geochemical interaction of greywacke with brine-NCG solutions under simulated reservoir conditions. The numerical simulations show that mineral dissolution occurred to a greater degree than precipitation, leading to increased permeability and porosity. It was also observed that the mineral reactive surface areas evolved as mineral dissolution progressed, through etch pit formation. Additionally, flow rate had an impact on the overall reaction rates such that a decrease in injection rate led to a corresponding decrease in reaction rates. Lastly, both experimental data and model outputs indicated that CO2 was minimally sequestered in the simulation, while H2S was clearly captured as pyrite. A similar numerical investigation was conducted on the co-injection of NCG with steam condensates subsequently. The modelling results indicate predominant mineral dissolution, CO2 is expected to be captured as magnesite within the reactor, while H2S is still captured as pyrite.

geothermal-energy.org

In this study, 3D visualization of temperature distribution in the Kizildere geothermal system an... more In this study, 3D visualization of temperature distribution in the Kizildere geothermal system and low resistvity distribution in Salavatli geothermal system were built using 3D interpolation and extrapolation techniques. The 3D visualisations are illustrated; ...

pangea.stanford.edu

PROCEEDINGS, Thirty-Sixth Workshop on Geothermal Reservoir Engineering Stanford University, Stanf... more PROCEEDINGS, Thirty-Sixth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, January 31 - February 2, 2011 SGP-TR-191 ... REINJECTION INTO LIQUID-DOMINATED TWO-PHASE GEOTHERMAL SYSTEMS

b-dig.iie.org.mx

Proceedings World Geothermal Congress 2010 Bali, Indonesia, 25-29 April 2010 ... Modelling of Inj... more Proceedings World Geothermal Congress 2010 Bali, Indonesia, 25-29 April 2010 ... Modelling of Injection into Vapour-Dominated Geothermal Systems ... Department of Engineering Science, University of Auckland, Private Bag 92019, Auckland, New Zealand e.kaya@ ...

International Journal of Greenhouse Gas Control

International Journal of Greenhouse Gas Control

This work addresses the feasibility of reinjecting H2S and CO2, captured and dissolved in effluen... more This work addresses the feasibility of reinjecting H2S and CO2, captured and dissolved in effluents from the geothermal field, back into the geothermal reservoir. A series of numerical modelling scenarios was used to assess the effect of NCG (non-condensable gases) reinjection on energy recovery, understand permanent trapping, and forecast potential NCG breakthrough into production wells. Although the gas species from geothermal systems typically have moderate solubility in water, formation of gas phases at lower pressures and/or the shallow subsurface requires careful consideration of the injection rate and composition of NCG. Possible fluid paths and distribution of gas components were investigated to estimate the NCG storage capability of a reservoir, and evaluate the potential risk of the reinjected NCG growing into fingers that may lead to an early breakthrough or potential leakage to the ground surface. Modified versions of benchmark geothermal reinjection models were constructed with initial conditions of a liquid-dominated geothermal system. The results obtained show that the effects of injection depend on the reinjection and production wells arrangement and the recharge conditions. The risk of leakage to the surface is very limited since the injected NCG remain in the liquid phase.